초록 ▼

A crash sensor including an accelerometer, a calculation device, a comparator, a trigger circuit, a physical quantity calculation device, and an adjusting device. The accelerometer develops an acceleration signal and the calculation device calculates a first value corresponding to a magnitude of dec

A crash sensor including an accelerometer, a calculation device, a comparator, a trigger circuit, a physical quantity calculation device, and an adjusting device. The accelerometer develops an acceleration signal and the calculation device calculates a first value corresponding to a magnitude of deceleration based on the acceleration signal. The comparator compares the first value and the trigger circuit actuates a protective device, such as an air bag, upon receiving the trigger signal from the trigger circuit. The physical quantity calculation device calculates a magnitude of physical quantities in a wave defined by acceleration signals during an initial stage of a crash. The adjusting device adjusts at least one of the first value corresponding to the magnitude of deceleration and the threshold value used by the comparator on a basis of the magnitude of physical quantities.

대표청구항 ▼

[ We claim:] [1.] A crash sensor, comprising:an accelerometer for developing an acceleration signal;calculation means for calculating a first value on a basis of said acceleration signal from said accelerometer , the first value corresponds to a magnitude of deceleration;comparator means for compari

[ We claim:] [1.] A crash sensor, comprising:an accelerometer for developing an acceleration signal;calculation means for calculating a first value on a basis of said acceleration signal from said accelerometer , the first value corresponds to a magnitude of deceleration;comparator means for comparing said first value with a threshold value and outputting a trigger signal when judging an occurrence of a crash from said first value exceeding said threshold value;a trigger circuit for actuating a protective device on receipt of said trigger signal from said comparator means;physical quantity calculation means for calculating a magnitude of physical quantities in a first wave, said first wave being defined by acceleration signals measured during times when a sign of a variation regarding said acceleration signals changes, and then becomes zero again in an initial stage of a crash, said measuring starts when said accelerometer initially develops a deceleration signal; andadjusting means for adjusting at least one of the following two parameters to be used in said comparator means in accordance with said magnitude of physical quantities in said first wave;(a) said first value corresponding to the magnitude of deceleration and(b) said threshold value.